Q: Can I Read Password from all W211 and W209 by IR?
If you have HC08 on W203 you can read the password by IR.
If you have W211 with HC12 in some cases you can read the password, that depends the MASK of the mcu.
Sometimes you have W203 on VIN but in EIS you have W209 or 211, they will be HC or ST12, on W209/211 you cannot read the password by IR, so need to take out the ezs and read by jtag or online calculation.
On does cases you need to have key v51 or v57 to take out the password, or if you have OBD communication you can use the online server to calculate the password for you.
Q: Is it safe to extract pass with server calculation on those cars(W203, W209, W211)? Because the working key will lose sync in the process and you will be left with no working key and no pass in the end. So if IR adapter can’t get pass and key is not v51/57 you will need to do EEPROM work??
If you have communication by OBD (without the blue cable plugged in) with W209/211 there is no problem to do online, even if you lost the key counter, you just need to take in and out like 7 times and let the key in the EZS for 1 minute and the key back to life.
Credit to DK VVDI MB experts.